Metal (Ag, Cu, Co)salts were mixed to reformed petroleum pitches for production of metal-containing carbon fibers. The carbon fiber was steam activated to investigate the microporosity and the behaviour of metal particles in activated carbon fiber. The melt spinning temperature of precursor pitch linearly increased as the metal content increased. Cobalt and copper-containing carbon fibers were decomposed after 400 ℃, silver-containing and non-metal containing carbon fibers were decomposed after 480 ℃ in air. The average pore diameter and specific surface area of non-metal containing activated carbon fibers were 20 Å and 1,100 m(2)/g. The activation rates of metal-containing carbon fibers increased by catalytic acceleration of metals. Average pore diameter and mesopore fraction of metal-containing activated carbon fiber increased as the metal content increased, however, specific surface area decreased. The metal-containing activated carbon fibers showed peaks corresponding to their own metal. Silver particles were uniformly distributed in activated carbon fibers, while copper and cobalt particles tended to coalesence and some of coalesced copper exited from activated carbon fibers resulting in macropores on the surface of activated carbon fibers during the steam activation.